fix(netstat): enable curated stats for tcp connections

[huntergregory]

Reduce cardinality of tcp_connection_stats by only keeping curated stats. Updates curated stats to include:

• timeouts
• loss probes
• loss retransmit

Curation was off, but there were already several curated stats for drops and errors.

Testing

I only see these stats after this change:

networkobservability_tcp_connection_stats{statistic_name="TCPLossProbes"} 233948
networkobservability_tcp_connection_stats{statistic_name="TCPLostRetransmit"} 143
networkobservability_tcp_connection_stats{statistic_name="TCPTimeouts"} 240

In a steady state cluster, the first stat seems to slowly increase over time, and the other two are constant.